Skip to main content

Table 1 Description of the general characteristics of the mothers, preterm newborns (PTNB) and full-term newborns (FTNB)

From: Vitamin D plasma concentrations in pregnant women and their preterm newborns

Variables PTNB Group FTNB Group p-value
N = 66 N = 92  
Characteristics of the mothers
 Age (n = 158) Years 26.0 ± 7.3 26.03 ± 6.8 0.987a
 Ethnicity (n = 158) White 18 (27.3%) 35 (38.0%) 0.151b
Black 6 (9.1%) 3 (3.3%)  
Mixed ethnicity 42 (63.6%) 54 (58.7%)  
 Schooling (n = 150) <  4 years 5 (8.5%) 2 (2.2%) 0.194b
4 to 8 years 50 (84.7%) 81 (89.0%)  
>  8 years 4 (6.8%) 8 (8.8%)  
 Number of pregnancies (n = 158) Number 2.2 ± 1.5 2.3 ± 1.5 0.761a
 Alcohol use (n = 158) Yes 5 (7.6%) 4 (4.3%) 0.492b
 Tobacco use (n = 158) Yes 13 (19.7%) 10 (10.9%) 0.169b
 Vitamin D Suplementation (n = 158) Yes 6 (9.1%) 5 (5.4%) 0.528b
 Folic Acid (n = 158) Yes 46 (70.8%) 92 (87.6%) 0.038b
 Iron (n = 158) Yes 50 (75.8%) 76 (82.6%) 0.320b
 Frequent use of sunscreen (n = 158) Yes 9 (13.6%) 23 (25.0%) 0.108b
 Regular exposure to sunlight (n = 158) Yes 5 (7.6%) 54 (58.7%) <  0.001b
 Pregnancy-induced illness (n = 158) Hypertension 27 (40.9%) 14 (15.2%) <  0.001b
Gestational diabetes 3 (4.5%) 2 (2.2%) 0.650b
Urinary tract infection 14 (21.2%) 32 (34.8%) 0.077b
 Prenatal care (n = 158) Yes (>  6 check-ups) 12 (18.2%) 71 (78.3%) <  0.001b
Yes (<  6 check-ups) 42 (63.6%) 16 (17.4%)  
No (no check-ups) 12 (18.2%) 4 (4.3%)  
 Pre-pregnancy BMI (n = 116) >  30 kg/m2 6 (19.4%) 19 (22.4%) 0.905b
25 to 29.9 kg/m2 8 (25.8%) 22 (25.9%)  
18.5 to 24.9 kg/m2 16 (51.6%) 39 (45.9%)  
<  18.5 kg/m2 1 (3.2%) 5 (5.9%)  
 Pregnancy weight gain High 18 (58.1%) 55 (65.5%) 0.720b
Adequate 7 (22.4%) 14 (16.7%)  
Low 6 (19.4%) 15 (17.9%)  
 Season (n = 158) Spring 14 (21.2%) 48 (52.2%) <  0.001b
Summer 24 (36.4%) 44 (47.8%)  
Fall 16 (24.2%) 0 (0.0%)  
Winter 12 (18.2%) 0 (0.0%)  
Newborn Characteristics
 Gender (n = 158) Male 35 (53.0%) 50 (54.3%) 0.727b
 Type of birth (n = 158) Vaginal 17 (25.8%) 48 (52.2%) 0.001b
 Gestational Age (n = 158) Weeks 29.8 ± 2.4 39.3 ± 1.2 <  0.001a
 Birth weight (n = 158) Grams 1250 ± 354.6 3317 ± 449.4 <  0.001a
 Size for gestational age (n = 158) Small for GA 14 (21.2%) 0.0 (0.0%) <  0.001b
Adequate for GA 47 (71.2%) 83 (90.2%)  
Large for GA 5 (7.6%) 9 (9.8%)  
  1. aAverage and standard deviation. Level of significance of Student’s t-test
  2. bNumber (percentage). Level of significance of the chi-squared test